Attachment-plug.



PATENTED FEB 18, 1908.

R. B. BENJAMIN.

' ATTACHMENT, PLUG. APPLIOATION-IY'ILED MAR; 25. 1907.

UNITED STATES PATENT OFFICE.

REUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS, ASSIGNOR TO BENJAMIN ELECTRIC MANU- FACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ATTACHMENT-PLUG.

Specification of Letters Patent.

Patented Feb. 18, 1908.

Application filed March 25. 1907. Serial No. 364,404.

To all whom it may concern:

Be it known that I, REUBEN B. BENJAMIN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Attachment-Plugs, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to improvements in that class of devices which are adapted to be inserted into a socket designed to receive an incandescent lamp and which are provided withcontacts for engagement with the contacts of the sockets and with flexible conductors leading from these contacts to a distant point at which current is to be consumed in a lamp, fan motor or other device requiring current. Such a device is known as an attachment plug, and, as commonly made, is provided with a threaded outer contact in the form of a shell and center contact, connection being made between these contacts and the contacts of the socket by screwing the plug into said socket. Such devices are unsatisfactory for many purposes, for the reason that several turns must be given the plug in screwing it into the socket and this rotation of the plug twists the cord or flexible conductor and causes the same to become kinked.

The object of my invention is to provide an attachment plug which may be inserted into an ordinary socket designed to receive an incandescent lamp, and which may be inserted into or removed from such a socket without being turned and which, when in place in the socket, will make the proper connections between its own contacts and the contacts of the socket. In the accomplishment of this object I provide a member formed of insulating material, and mount upon this member a center contact adapted to engage the center contact of the socket and an expansible outer contact adapted to engage the outer contact member of the socket when the device is inserted into such socket. I also combine with the above-named parts means tending to expand the outer contact and means whereby the same may bemanually contracted when it is desired to insert the device into the receiving socket. Suitable means are also provided for making electrical connection between the ends of the flexible conductor and the center and outer contacts of the device.

In Figure 1 of the drawings I have shown, in central longitudinal section, a form of device embodying the features of my invention; Fig. 2 is a view similar to Fig. 1, but showing the parts in a different position, as will be explained hereinafter Fig. 3 is a plan View looking at the end of the plug portion of the device; Fig. 4 is a plan view of the opposite end of the device with the cover which is designed to conceal the binding-screws, removed; Fig. 5 is a cross-section of the device taken on the line 55 of Fig. 1 looking in the direction indicated by the arrows; Fig. 6 is a cross-sectional view, the section being taken on the line 66 of Fig. 1; looking in the direction indicated by the arrows; Fig. 7 shows a central longitudinal section of a modified form of device, the section being taken on the line 77 of Fig. 9; Fig. 8 is a plan view of one end of the device; and Fig. 9 is a crosssectional view of the same, the section being taken on the line 99 of Fig. 7.

Referring first to Figs. 1, 2, 3, 4, 5 and 6, 10 is a base formed of porcelain or other suitable insulating material. Secured to this base 10 are corrugated contact strips 11, these strips being preferably three in number. These strips 1 1 are each formed with an end 12 bent at substantially a right angle with the main body-portion of the strip and a screw passes through the end 12 and a suitable openingin the base 10, these screws being designated 13, 13" and 13 The opposite side of the base is provided with a square recess 14 and a curved recess 15. In the square recess 14 is located a nut 16 into which passes the screw 13 which holds one of the strips 11 in place. The other two screws 13 and 13 pass into a curved plate 17 which is located in the curved recess 15, the plate 17 being provided with a binding-screw 18 adapted to receive the end of one of the supply wires. Electrical connection is thus made between the supply wire and two of the corrugated strips 11..

Located between the strips 11 is a plug member 19, formed of porcelain or other suitable insulating material. This plug member 19 is provided with a cylindrical chamber in which is disposed a spring 21, this spring beingseated against a shoulder 22 and tending to move the plug 19 and base 10 away from each other. Extending centrally through the chamber 20 is a bolt 23. This bolt forms the center contact of the device and is rigidly secured to the base 10, through which it passes. This bolt is pr0- vided with a nut 24 and washer 25 against which the spring 21 thrusts. The base 10 is formed with a recess 26 in which is located a plate 27 into which passes the bolt 23. This plate 27 is provided with a binding-screw 28 adapted to receive the other supply wire. The plug member 19 is formed with an enlarged portion 29 provided with a skirt 30,

this skirt surrounding a portion of the base 10 and telescoping therewith. The enlarged part 29 is formed with three openings 31 through which extend the strips 11. The plug 19 is formed with three channels 32 extending along the sides of the plug. In each of these channels lies one of the strips 1].. Toward the end of the plug 19 these channels have their bottoms inclined inwardly or to- -ward the center of the plug and the outer end of each of the strips 11 is bent inward and rests upon the inclined portion of the bottom of the groove or channel.

When the plug portion 19 is extended under the action of the spring 21, as shown in Fig. 1, these spring contact-strips 11 are forced apart by the wedge-like action of the plug 19. When the plug 19 is thrust inward relative to the other parts of the device and against the pressure of the spring 21, as shown in Fig. 2, the inturned ends of the strips 11 ride down the inclined bottoms of the channels and the spring strips 11 are permitted to move inward or toward each other.

An outer cover or casing in the form of a metallic shell 33 is adapted to protect and conceal the contact screws 18 and 28. 'This shell 33 is formed with a central opening into which is inserted an insulating bushing 34. The flexible conductors are brought in through this bushing 34 and secured to the proper binding-screws. The shell 33 is preferably lined with a fiber shell 35.

The operation of the device is as follows: The plug 19 and base 10 are manually thrust toward each other by the person using the device and against the pressure of the spring 21 which tends to separate these parts. This collapsing of the device permits the spring contact strips 11 to approach each other, the

inturned ends of the strips riding down the inclines and moving toward each other and toward the center of the plug 19. If the plug be now inserted into a lamp-receiving socket the end of the screw 23 will engage the center contact of the socket. When released, the

base 10 and strips 11 carried thereby will be forced backward. and away from the center contact by the action of the spring 21, this and 53.

and at the same time connection is made between the bolt 23 and the center contact of said socket.

In the form of the device shown in Figs. 7, 8 and 9 the construction is somewhat modilied. In this device a plate 36 is secured to the base 37 by screws 38 and 39 and into this plate 36 is screwed the end of the bolt 40 which forms the center contact of the device. The movable plug 41 is provided. with a cylindrical chamber containing a spring 42 seated against the plate 36 and tending to thrust the plug 41 away from the base 37. This plug member 41 is formed with three channels 43. The strips 44 extend through openings 45 in the plug 41, and have each an outer end 46 bent inward or toward the center of the plug 41, and lying within the channels 43, the latter being formed. with inclined portions 47 upon which the ends of the plates 44 ride. One of the strips 44 is secured to the base 37 by a screw 48, the other two strips 44 being secured to a plate 49 by screws 50 and 51.. This plate 51 is provided with a binding-screw 52. The plate 36 is also provided with a bindingscrew 53. The base 37 is formed with a central opening 54 through which may pass the flexible conductors to the binding-screws 52 The plug 41 is formed with skirt 54 adapted to telescope over the base 37.

It willbe seen that, broadly regarded, my invention contemplates the use of an expansible outer contact member adapted to be expanded by the movement away from each other of two parts of a telescoping plug.

In the embodiment of my invention herein shown and described I employ a plurality of members adapted to engage the shell of a lamp-receiving socket and tending normally to approach each other and to move away from said shell, combined with a wedging member adapted to be thrust in between said contact members and to force them apart and into engagement with the socket.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an attachment plug, the combination of a base, a plug carried thereby and movable relatively thereto, a plurality of corrugated strips secured to said base, means carried by the plug for spreading said. strips,

and spring means tending to move said plug from theaxispfthe plug ,when said ;plug is r d. avarf i he awns sp i m s tendingto move said plu g away from saidbase In an,,attachment ,plug,.the combina tion of a base, a plurality of corrugated stripsarranged concentrically. aboutjtlie axis of said base, a plug movable toward and away r the axis thereof, a movable plug disposed between said strips and adapted when moved away from said base to separate said strips, and spring means adapted to move said plug and base away from each other.

5. In an attachment plug, the combination of a base, a corrugated strip having one of its ends secured to said base, a plug movable relatively to said base, said strip extending along the side of said plug, means on said plug adapted to engage said strip and move the same away from the center of the plug when the plug moves away from the base, and means tending to move said plug away from said base.

6. In an attachment plug, the combination of a base, a plug movable relatively thereto, a plurality of contact members arranged around said plug and adapted to engage the outer contact of a socket, and means for causing'said contact members to move away-from each other when the plug is moved away from the base, and spring means for moving said base and plug away from each other.

7. In an attachment plug, a base, a plug movable relatively thereto, a spring tending to move said base and plug away from each other, a sectional outer contact arranged longitudinally of said plug and adapted to be expanded by the movement of said plug. away from said base, and a center contact secured to said base and extending through the plug.

8. In an attachment plug, the combination of a base, a plug movable toward and away from said base, means tending to separate said plu and base, a sectional outer contact memIier arranged along said plug and adapted to be expanded by the movement of said plug and base away from each other, a contact arranged centrally of the plug, and binding screws for making connection with said center and outer contact members.

9. In an attachment plug, the combination of a base having an expanding outer contact on one, of its sides, binding-screws upon its opposite side electrically connected with said outer contact, a bolt passing centrally through said base, a binding-screw electrically connected, with; said, bolt a p g u din id ql t- Plus qv bla e t ve to the a id a apt J e. a ed way mm.la d ase y aid pr g a mat .a tt warhea d p ed; pand id t r-z osta tams bere ha moved c ass e s th -s id er es! 10. In attachment plug, the combination of a base and plug movable toward and away from each other, a spring tending to separate said base and plug, and a contact member arranged longitudinally of said plug and adapted to be moved away from the axis of said plug when said plug and base are moved relatively to each other by said spring.

11. In an attachment plug, the combination of a base and-plug movable toward and away from each other in the direction of the axis of the plug, means carried by said base and adapted to be expanded by the move ment of said base and plug away from each other and when so expanded to engage the outer contact of a socket, and binding screws located in the space between said plug and base.

12. In an attachment plug, the combination of a relatively-movable base and plug, a center contact extending through said plug and secured to said base, an expanding outer contact carried by said base and inclosing said plug, and a spring surrounding said center contact and adapted to force said base and plug away from each other and thereby to expand said outer contact-member.

13. In an attachment plug, the combination of a base, a plug movable toward and away from said base, acontact-member extendin longitudinally through said plug and secured to said base, spring means tending to separate said plug and base, and an outer contact carried by said base and adapted to be expanded by the movement of said base and plug away from each other.

14.. In an attachment plug, the combination of a base having a central aperture through which conductors may be led, binding screws upon the inner side of said base, expanding outer contacts secured to said base and electrically connected with said binding-screws, and a plug movable toward and away from said base and adapted by its movement away from said base to expand said outer contact.

15. In an attachment plug, the combination of a relatively-movable base and plug, an expanding outer contact-member carried by said base and adapted to be expanded by the movement of said plug and baseaway from each other, said base having an aperture through which conductors may be led to the space between said base and plug, and a binding-screw located in said space and electrically connected with said outer contact-member.

16 In an attachment plug, the combina- In Witness whereof I have herennto subtion of a base, a plug movable relatively to I scribed my name in the presence of two Wit said base, an outer contact member carried nesses.

by said base and adapted to be expanded by REUBEN B. BENJAMIN. 5 the movement of said plug relative to said Witnesses:

base, and means tending to move said plug W. PERRY HALEY,

in the direction to expand said contact. 0. L. HOPKINS. 

